Seminar by Prof. Dr. Le Khanh Chau and Dr. Le Thi Cam Tu

On May 12, 2023, the lecture from Prof. Dr. Le Khanh Chau and Dr. Le Thi Cam Tu talk place in meeting room B.

Prof. Dr. Le Khanh Chau presents a talk entitled "Thermodynamic theory of dislocation/grain boundary interaction".

Abstract:

The thermodynamic theory of dislocation/grain boundary interaction, including dislocation pile-up against, absorption by, and transfer through the grain boundary, is developed for nonuniform plastic deformations in polycrystals. The case study is carried out on the boundary conditions affecting work hardening of a bicrystal subjected to plane constrained shear for three types of grain boundaries: (i) impermeable hard grain boundary, (ii) grain boundary that allows dislocation transfer without absorption, (iii) grain boundary that absorbs dislocations and allows them to pass later.  

Dr. Le Thi Cam Tu presents a talk entitled "Visualization of dynamic core-electron polarization effect using Bomhian trajectories".

Abstract:

Within the framework of the single-active-electron approximation, the key role of dynamic core-electron polarization (DCEP) in the description of strong-field processes such as ionization and high-order harmonic generation of polar molecules such as CO has been revealed. Specifically, in the harmonic process, the origin of DCEP is tracked back to the ionization step at some specific instants. For a complete physical picture, offered by Bohmian mechanics, we have developed a visualization tool called Bohmian trajectory analysis. Based on this, we can explain not only qualitatively but also quantitatively the effect of DCEP on the harmonic process. Moreover, the inherent nonlocality of the Bohmian trajectory is also demonstrated.